I have no problems running D1 and D2 using DOSBox, except for one thing - in both games, with my current settings I get a delay of like 3-4 seconds between pressing TAB and getting my Automap. Switching back to gameplay is the same. I don't remember having this problem back in the day when I played on Windows 95, or even in earlier DOSBox emulations of my own. Does anyone have any idea what could cause this behavior, and what options or command line parameters to use to make it go away?

I have the DOSBox version of D1, D2 from GoG, and don't have this bug. Probably related to DOSBox settings. I have Win7 x64. Probably can upload my version so you can test it - if you need.

Please do! I've been experimenting with various CPU settings for Dropbox, but none of them affected this issue, be it D1 or D2. I tested the game on my level, The Cauldron, where there is one very cube-intensive area that taxes the emulated CPU core, and I've been able to get smooth performance using the Dynamic core setting, but that comes at the cost of the game speeding up beyond its intended speed in areas where few cubes are within your range of sight, so it's not a workable solution. I'd really like to see your settings, since I'm using Windows 8.1, so they should match I guess.

I still have this issue even in the GOG version. Must be something with my hardware or something else, then.

This issue is absent on a virtual machine with Windows 2000, so I assume that my system being Win 8.1 is at the root of the issue, whether it's the particular version or just the fact that it's 64-bit. I think it would probably be optimal to just play Descent and D2 on a virtual machine with Windows 95/98, which have native DOS support.

My system is Windows 7 x64, and it seems I made the right choice by immediately deleting Win8 as I bought this laptop (where I have Descent installed), and installing Win7!
Yes could be issue with video card, driver, etc, possibly the delay is caused by change of video mode or resolution (but I don't know why it became different in Win8). Using VM seems to be a good idea, but probably Win10 (or Win7) won't have this problem on your machine, too.

Well I got 8.1 installed on my machine when buying it, it was recommended to me by the vendors who said Win10 might no longer support all of the hardware I have there. Weird, since it's rather fresh still. Anyway, I'm using Classic Shell, so I don't have to struggle with all the bullcrap that came with Windows 8. Anyway, when I pause the game in DosBox, the music cuts and it takes around 3 seconds for the automap to show, same when reverting back to the gameplay. No idea in the world what could cause it, and it's rather aggravating for someone like me who checks out the Automap every 10 seconds, lol

Same story, vendors told me I have to keep the pre-installed system (Win , I did not want to, in addition to it's bugs and problems (found about the Classic shell only about a year later) I don't like to work on a system without full installation CD. Had problems with the drivers when installing Win7, but found everything at last. People say Win 10 is much better, still a bit afraid of it because many people tell that it has built-in spyware... Yes, having the automap delay does not look fun, probably it can cause problems with demo recording, too...

The "built-in spyware" is telemetry collection, which is not supposed to be personally identifiable, but it's not my place to lecture anyone over whether or not they should be OK with it. I will say that telemetry apparently also exists in Windows 7, though, even if it isn't used anywhere near as heavily there. It really only became a huge part of the process after the "agile development" ideology made its way into Windows in order to ship every few months rather than years.

I used to disable everything I don't need in Win 7 (like services, scheduled tasks, all sorts of crap I don't need) to make work and load faster, probably this telemetry is also disabled on my Win 7. And probably possible to disable it on Win10, if you know how... But I care more about unnecessary background apps eating up computer resources than about real harm from spyware. Probably if Win10 worked faster -and not interfered with old games - I'd give it a try. Agile development scares me a bit, they'd better care about fixing bugs and making OS and "core" software faster than delivering anything "new". Word and Excel load for a minute before opening empty document on my machine, where previous versions did it instantly, same about new VS (fortunately VS is much faster with an SSD).

Do you have the automap set to a different resolution than the main game? I'm wondering if it is some glitch from mode switching, it has been ages since I've checked what options were available in the old DOS native D1x and D2x versions, but make sure your automap isn't jumping up to some higher/different resolution than the main game window. Something like that would probably be stored in the D1x/D2x player config so if you copied that over it would cause the same issue even on different installs.

Do you have the automap set to a different resolution than the main game? I'm wondering if it is some glitch from mode switching, it has been ages since I've checked what options were available in the old DOS native D1x and D2x versions, but make sure your automap isn't jumping up to some higher/different resolution than the main game window. Something like that would probably be stored in the D1x/D2x player config so if you copied that over it would cause the same issue even on different installs.

That's an interesting observation, I might look into it today. Never really thought that was even possible tbh, thought all the game was rendered within a single resolution.

It's definitely not stored in player data though, since I created completely new players in the GOG installation folder and the issue persisted. It didn't when i ran the installation on a Win2k virtual machine though (however the game was still unplayable due to a less than optimal CPU core configuration). Also, I can't go fullscreen when playing within a virtual machine, so I'd be much happier if I could play it under my core system.

Two issues to fix:
- slowdowns in cube-heavy areas (rare) - fixed by setting the cpu cycles to max and the core type to dynamic, but this comes at the cost of the game actually running faster than it should in sections where there's little to render. Normal cpu core settings run the game fine in most sections, but it does slow down occasionallly (like The Cauldron, yeah)
- The weird automap delay

Fix those two things and I'll be able to play the game on DOSBox finally. Too bad I have no idea how

The slowdowns in cube-heavy areas are basically emulating a fact of life on old 486s that weren't too fast to run the game without breaking it. They didn't have a framecap until the 3dfx versions came out. If DOSBox could emulate a Voodoo 2 you'd be pretty much sorted, but I have a feeling that isn't coming.

One cheap way to test if it's a resolution switching issue is by running DOSBox in windowed mode. Window resizes are a lot faster than a real display mode change.

DOSBox doesn't only emulate 486s though, it can go up to Pentium III, depending on how powerful your own CPU core is. GPU emulation is another thing altogether though.

I wish I could just get a Win98 virtual machine, then I could play the game through the system's native DOS functionality. Oracle VirtualBox doesn't have extended support for Win9x though, which means there is no way to establish a file exchange between the VM and your native system. In other words - no way to transfer Descent onto the virtual disk. Does anyone know if there are other VM environments apart from Oracle's that are not restricted by this?

Well, yeah, but if you have it running at Pentium 3 speeds it's going to be breaking 200 fps on a regular basis, which the D2 game loop isn't designed to handle properly. Unfortunately there isn't really any reason a Win98 VM wouldn't do the same thing. You can try to aim for a "sweet spot" where it neither runs too fast nor too slow, but there's probably still going to be some monster of a level that can make it chug. Framecaps are the only good solution, but D2 DOS didn't have one. (There's no DOS version of D2X either, unlike D1X.)

Well I guess I shouldn't bother and just stick to the source ports. The way robot explosions were done in Rebirth does bother me, and I also enjoy some retro touches that the original DOS versions have. Otherwise though there are going to be more and more reasons to stick to Rebirth, since support for old-school rotating robot briefings from D1 is coming soon, and I really liked those